Apparatus for boiling liquids



Jan. 13, 1931. v E. ALTENKIRCH 8 APPARATUS FOR BOILING LIQUIDS Fi1ed June 1, 1935 2 Sheets-Sheet 1 Jan.l3, 1931. E. ALTENKIRCH 1,788,818

APPARATUS FOR BOILING LIQUIDS I Filed June 1', 1925 2 Sheets-Sheet 2 am Mal Patented Jan. 13, 1931 UNITED STATES V 1',7ss,31s

PATENT OFFICE,

nnfiom) ALTENKIRCH, or ALT-LANDSBEBG-SUD, GERMANY, ASSIGNOR TO SIEMENS- sonucxnn'rwnnxn GESELLSCHAFT MIT BESGHRANKTER HAFTUNG, OF SIEMENS- STADT, NEAR BERLIN, GERMANY, A CORPORATION or GERMANY APPARATUS FOR BOILING LIQUIDS Application filed June 1, 1925, Serial No. 34,051, and in Germany June 3, 1924.

My invention relates to improvements in apparatus for; boiling liquids. In boiling liquids which should not 'be completely evaporated but part of which only should 5at first be converted into vapor, it is frequently advisable to pass the liquid in a uniform stream through the boiling chamber. It is alread known to obtain the necessary motion of the liquid Without the application of anyspecial circulating apparatus by passing the liquid together with the vapor developed through an ascending pipe. The vapor bubbles rising in this pipe carry the liquid along and at the rate at wh ch it 1s discharged at the top of the ascending plpe it enters the pipe at the bottom.

According to my invention a particularly uniform boiling of the water is attained by providing the ascending pipe with traps for zu the steam. Such a device is particularly advantageous for such liquids which show a considerable retardation of boiling. The rising pipe may be heatedfrom the outside 1n order that it may itself serve as boiling chamber.

The drawing afiixed to my specification and forming part thereof shows a number of embodiments of my invention.

Fig. 1 v is a vertical section through a so simple plant, 7

Fig.2 another construction of boiler and Fig. 3 a plant for dehydrating gdiluted sulphuric acid embodying my invention.

Referring to Fig.1 the liquid to be boiled is contained in a-storage tank 1-which communicates with a coil 2. This coil is locatedin "a heating chamberB into which heatinggases enter at 4 and escape at 5.- When the boiling process starts the level of the liquid in the coil 2 is at the same'height as-the level of the liquid in the tank 1. As soon as I the water in the coil 2 starts boiling the steam bubbles generated drive the liquid in front of them. The li uid is in this way conveyed into the tank 10 rom which the steam is able to escape through the outlet pipe According to my invention the coil 2 1s provided with trapping chambers 7,8, 9 in which the steam, or e'nerally speaking the vapor, is m caught. ractical experience has proved.

that-these traps have a decisive influence upon the boiling process and render it more uniform, an advantage which is the more. pronounced the greater is the retardation of boiling of the liquid. If, for'instance, vapor is to be expelled from diluted sulphuric acid by heating, a considerable amount of super-' heating is necessary. The boiling then starts so suddenly and with such violence that the liquid is not only ejectedat the top. of the 6 pipe 2 but also at the bottom' When cold liquid enters the pipe 2 from the tank 1 the boiling would cease in a smooth uniformly ascending pipe until thenext boiling surge occurs. A uniform boiling process and a um- 5 form stream of liquid through the pipe 25 upwards into the receiver 10 couldnot poss'ibly take place under these circumstances.

If, however, according to-my invention vapor is trapped in the chambers or spaces 7 8, 9, the retardation of boiling will obviously be suppressed at the points of contact between vapor andliquid. In any case it can.

be clearly observed that atthe places where vapor has been trapped a continuous surgefree development of vapor takes place. The

ascending steam bubbles carry the liquid in the pipe along in a uniform stream and the boiling takes a quiet and steady course assuming a s'uificient supply of heat. If it is so desired that the same liquid be subjected to the boiling process a number of times, itis only necessary to return the liquid by acounecting pipe from the vessel 10 back into the tank'l. chambers may be of spherical shape as at 7 others may consist simply of. cavities suchasat8and9.

i A further modification of the invention is i illustrated in Fig. 2. The boiling pipe 12 is in this case led upwards in one plane but bent in sine wave fashion so that upwardly directed portions alternate with downwardly directed portions. At the places 17, 18, 19, 20

at 'whichhe pipe turns downwards steam bubbles remain stationary when the boiling liquid passes alon the pipe and ensure a steady progress 0 the boilirfilg operation as specified with'referjence to ig. 1.: At the turning point 17 novapor collects if the liquid m0 Some of the vapor trapping 85 Boiling apparatus of this kind is particularly suitable for expelling water from diluted sulphuric acid, for concentrating salt solutions and many other purposes.

In Fig. 3 the application of my invention for the dehydration of diluted sulphuric acid for the operation of an absorption refrigerating machine is illustrated; The low temperature is generated in an evaporator 31 by evaporating therein water at low pressure. The stream passes through a pipe 32 into an absorber 33 which is fed with a concentrated sulphuric acid solution by the pipe 34. The

steam is absorbed by the sulphuric acid in the absorber and the heat set free during the absorption is transferred to the surrounding atmosphere. For this purpose the absorber 33 is provided with radiator fins. The sulphuric acid solution diluted with water reaches the collecting vessel 35 and flows through the pipe 36 towards the lower end of the boiling pipe 37. This boiling tube is heated by an electric heating element 38. It is a smooth spirally wound pipe the axis of which is disposed obliquely so that each turn of the coil consits of an upwardly directed portion and a downwardly directed portion. At the turning points between the two portions steam is detained in the same manner as described with reference to Fig. 2 and thus. a uniform generation of steam and supply of liquid ensured. The simple manner of manufacture of such a pipe and the large number of trapping spaces renders this construction particularly valuable. The ascending mixture of steam and liquid reaches a gas separating chamber 39 from which the liquid is returned into the absorber 33 through the pipes 40 and 34. The expelled steam accumulates in the steam dome 41 and is led into a condenser formed by a worm-shaped pipe 42 provided with radiation fins. The water condensed in this condenser ascends through the pipe 43 into the evaporator and is here again evaporated.

What I claim as my invention is: .1. An absorption machine having mean for expelling the operating medium in Vapour form from the absorption liquid, comprising an ascending tubular element for raising the absorption liquid by the ascending medium vapour, means for heating said element to expel the operating medium, said tubular element having sections with suitably inclined wall portions for trapping some of the vapour bubblies in said sections, means for receiving -the empoverished liquid discharged at the upper tube end, means for conducting away the vapour expelled from the liquid, means for bringing the operating medium and absorp tion liquid again into contact to form a solution, and means for conducting said solution to the lower end of said tubular element.

2. In a refrigerating system, the combination of a boiler for expelling a refrigerant as a gas from an absorption liquid upon the application of heat thereto, a chamber associated with the boiler adapted to receive the gaseous refrigerant and the absorption solu tion from the boiler and separate the same,

an absorber for causing the absorption liquid to absorb the gaseous refrigerant expelled from the boiler, and conduits connecting the boiler, gas separating chamber and absorber to form means for circulating the absorption solution therebetween, said boiler also func tioning to cause circulation of the absorption solution and having means for preventing violent surges of the solution therein.

3. In a refrigerating system, an absorber, a gas separating chamber, conduits connecting the same to form means for circulating an absorption solution therethrough and a gas lift pump in one of said conduits operable upon the application of heat thereto to cause the formation of bubbles in the solution to cause the same torise, and said pump having means for preventing violent surges of the ..t1ons arranged to cause the formation of gas pockets in said pipe to prevent violent surges of solution therein.

5. In a refrigerating system, a device for circulating an absorption solution and for expelling a refrigerant therefrom upon the application of heat thereto, said device consisting of a coil of pipe of small diameter, the longitudinal axis of which is inclined with respect to the vertical whereby gaspockets are formed in portions of the coil and facilitate uniform boiling of the solution without surges. I

6. A device for circulating a solution and for expelling the solute therefrom comprising a pipe of small diameter adapted to cause bubbles formed therein to be interspersed between slugs of the solution to thereby cause the same to rise and having means for preventing violent surges of thesolution therein.

7. In combination a device for circulating a solution and for expelling the solute therefrom comprising a pipe of small diameter adapted to cause gas bubbles formed therein to be interspersed between slugs of the solution and having means for preventing Iiolent surges of the solution therein, a chamber associated with said device for receiving both the gas and the solution. therefrom and for ping vapors.

- nveaeia causing the separation of same and a meanstion'to the inlet end of said conduit, means for returning the solution to said'device.

8. A circulatory system containing two mutually soluble liquids having difierent boiling points, said system comprising a heating section for circu ating the liquids and for boiling the liquid of lower boiling point out of the other liquid, said heating section consisting of a conduit arranged in a non-horizontal position and a heating device associated there'- with, said conduit having means therein for trapping vapors. v 9. A circulatory system containing two mutually soluble liquids having difi'erent boiling points, said system comprising a heating section for circulating th'eliquids and for'boiling the liquid of lower boiling point out of the other liquid, said heating section consisting of a conduit arranged in a non-horizontal position and a heating device associated therewith, said conduit having vapor traps distributed along the interior thereof.

10. A circulatory sstem containing two mutually soluble liqui s having different boiling points, said system comprising a heating section for circulating the li uids and for boiling the liquid of lower boi ing point out of the other liquid, a chamber adapted to receive the liquid and vapor from said heating section andto separate them, means for separately conveying away the liquid and vapor from said chamber, means for condensing the vapor, and means for bringing the condensate and the other liquid together and for con- I jected in said system and being capable of veying the resulting solution to said heating section, said heating section comprising a conduit arranged in a non-horizontal position and a heating device associated therewith, said-conduit having means therein for trap- 11. An absorption system containing twofluids having diflerent boiling points, the

- absorbing the other fluid, said system comprising means" for-bringing said fluids into contact to produce a solution, aconduit arran ed in a non-horizontal osition means g p to ascend and be discharged through said outfor guiding said solution into the lower end of said conduit, means for heating said con- 'duit to vaporize the fluid of lower boiling adapted to receive the fluids discharged therefrom and allow them to separate.

121 A device forseparating into its constituents a solution of two fluids, at least one of which is'a liquid, and which have difierent boiling points, said device comprising a conduit arranged in a non-horizontal position having an inlet at its'jlower end and an outlet at its upper end, means for feeding the sal a.-

for heatin the solution in' said conduit to va 'orize t e fluid having the lower boiling point and to thereby cause the fluids in said conduit .to ascend and be discharged through said outlet, means in said conduit for tra ping vapor, and means for receiving t e liquid discharged from said outlet. 13. A device for separating into its constituents a solution of two fluids, at least one of which is a liquid, and which have different boiling points, said device comprising a conduit arranged in a non-horizontal position having an inlet at its lower end and an outlet at its upper end, means for feeding the solution to the inlet end of said conduit,- means for heating the solution in said conduit to vaporize the fluid having the lower boiling point and to thereby cause the fluids in said conduit to ascend and be discharged through said outlet, said conduit havin sections with suitably downwardly incline wall portions for trapping vapor.

14. A device for separating into its constituents a solution of two fluids, at least one of which is a liquid, and which have difl'erent boiling points, said device comprising a con duit arranged in a non-horizontal position havin an inlet at its lower end and an outlet at its. upper end, means for. feeding the solution to the inlet end of said conduit, means for heating the solution in said conduit to vaporize the fluid having the lower boiling point and to thereby cause the fluids in said conduit to ascend and be discharged through said outlet, said conduit consisting of alternately u wardlyand downwardly inclined sections orming vapor traps.

15. A device for separating into its con stituents a solution of two fluids, at least one of which is a'liquid, and which. have different boiling points, said devicecomprising a' conduit arranged in a I non-horizontal position having an inlet at its lower end and an outlet at its upper end, means for feeding the sol ution to the inlet end of said conduit, means for heating the solution in said conduit to vaporize the fluid having the lower boiling point and to thereby cause the fluids in said conduit let, said conduit consisting of a spiral tube upwardly inclined in its general direction, the inclination of the axis of the spiral being such that the spires of the tube form alter nately upwardly and downwardly inclined 12o sections forming vapor traps.- I

In testimon whereof I afiix my signature.

- I DMUND ALTENKIRCH, 

